Some users like to create a new Upload Set each time they add assets to their account, but others prefer to maintain a short list of Upload Sets that they regularly update with new work. Note that you can upload single files, groups of files, or entire folders of content into one upload set. Follow these steps to add more assets to an existing Upload Set.
Add to an Upload Set
Go to the Assets tab
Scroll until you see the section titled Sets
Click Upload Sets
Locate the desired set by either scrolling or using the search bar in the upper right
Click on the Upload Set’s name
Click the blue “Add Files” button in the upper right
Drag and drop or upload your assets into the window
Wait for your files to finish uploading and processing before leaving the page. If you exit the page before the assets finish processing, they will not be saved.